Bean Game
After you have taught the reef knot you give everyone one bean. They then go in pairs and see who can tie the knot the fastest. The fastest one gets the other one's bean which now means they have two. Girls with two beans find each other and repeat tying the knot. The one who ties it the fastest gets the beans and therefore now has 4 beans. She goes to find another person with four beans and so on. For the girls who lose they just go and get another bean from the pot and start out again so no one really loses and everyone gets lots of practice with this one knot.